Chemistry of aromatic polythioesters and polydithioesters

Abstract

Aromatic polythioesters and polydithioesters with different numbers of methylene units have been synthesized and characterized in terms of solubility, crystallinity, glass transition, melting, thermal decomposition, molecular motion, and thermal transition.

Semiaromatic Poly(thioester) from the Copolymerization of Phthalic Thioanhydride and Epoxide: Synthesis, Structure, and Properties

“…Later, Podkoscielny and colleagues prepared semiaromatic poly­(thioester)­s by interfacial polycondensation. Here, a series of dithiols dissolved in sodium hydroxide were reacted with dicarboxylic acid dichlorides dissolved in an organic solvent, such as chloroform, benzene, or hexane. − More recently, Sasanuma et al reported an improved synthesis of semiaromatic poly­(dithioester)­s involving an ionic polycondensation reaction between tetrathio­terephthalic acids complexed with piperidinium and α,ω-dibromoalkanes. , However, their strong and unpleasant odor limits the use of thiols and thiocarboxylic acids for the development of semiaromatic poly­(thioester)­s. Biosynthesis of poly­(thioester)­s is of great interest as an alternative, environmentally benign means of meeting green polymer chemistry requirements. − Additionally, the ring-opening polymerization of thiolactone or thionolactone is a more common method for synthesizing poly­(thioester)­s. − However, as far as we know, only aliphatic poly­(thioester)­s have been produced with these two methods, and no examples of semiaromatic poly­(thioester)­s have been reported.…”

Structure–property relationships of aromatic polyamides and polythioamides: comparative consideration with those of analogous polyesters, polythioesters and polydithioesters

“…For the energy parameters of the polythioesters and polydithioesters, see the original papers. 4,5 The data on the polyesters are quoted from the literature. 1,3 The characteristic ratios (hr 2 i 0 /nl 2 ) and congurational entropies (S conf ) are shown in Table 6, and the hr 2 i 0 /nl 2 ratios were calculated with the virtual bond connecting the two C]X (X ¼ O or S) carbons (see Fig.…”

“…In previous studies, we investigated the conformational characteristics and congurational properties of aromatic polyesters [1][2][3] and designed, synthesized, and characterized novel aromatic polythioesters and polydithioesters 4,5 (Fig. 1).…”

Molecular Design of Aromatic Polythionoesters

“…In previous studies, we investigated conformational characteristics and structure–property relationships of aromatic polyester and polythioesters expressed by chemical formulae given in Figure : X = Y = O, poly­(ethylene terephthalate) (PET); X = O and Y = S, poly­(ethylene dithioterephthalate) (PETS 2 ); − X = Y = S, poly­(ethylene tetrathioterephthalate) (PETS 4 ). − In Table , their conformational characteristics and configurational properties are summarized. These polymers, because of lack in side-chain motions, that is, poor in entropic advantages, are hardly soluble in common organic solvents.…”

“… a In a benzene environment (dielectric constant = 2.27) at 25 °C. See Figure . b From free energies at the MP2/6-311++G­(3df,3pd)//B3LYP/6-311+G­(2d,p) level. c From free energies at the MP2/6-311+G­(2d,p)//B3LYP/6-311+G­(2d,p) level. − d cis and trans. − e trans–trans, (trans–cis) ± , (cis–trans) ± , and cis–cis …”